Radiation Power Level Control System and Method for a Wireless Communication Device Based on a Tracked Radiation History

ABSTRACT

A radiation power level control scheme for a wireless user equipment (UE) device. In one embodiment, a method comprises determining a time-average transmission power level, comparing the time-average transmission power level with a first time-averaged transmission power limit threshold, the first time-averaged transmission power limit threshold having a value that depends on a transmission power history for the UE device, and responsive to the time-average transmission power level meeting or exceeding the first time-averaged transmission power limit threshold, reducing a transmission power level of the UE device.

CLAIM OF PRIORITY UNDER 35 U.S.C. §120 & 37 C.F.R. §1.78

This nonprovisional application is a divisional application claiming thebenefit of the following prior United States patent applicationentitled: “RADIATION POWER LEVEL CONTROL SYSTEM AND METHOD FOR AWIRELESS COMMUNICATION DEVICE BASED ON A TRACKED RADIATION HISTORY”,filed Jul. 20, 2010, application Ser. No. 12/839,622 (Attorney DocketNo. 1400-1205US; Client No. 37962-US-PAT), which is hereby incorporatedby reference.

INCORPORATION BY REFERENCE TO RELATED APPLICATION(S)

This application discloses subject matter that is related to the subjectmatter of the following U.S. patent application(s): (i) “TRANSMISSIONCONTROL FOR A SPECIFIC ABSORPTION RATE COMPLIANT COMMUNICATION DEVICE”,application Ser. No. 12/536,339; filed Aug. 5, 2009; and (ii)“MODULATION AND CODING SCHEME SELECTION METHOD FOR A SPECIFIC ABSORPTIONRATE COMPLIANT COMMUNICATION DEVICE”, application Ser. No. 12/722,362;filed Mar. 10, 2010, now issued as U.S. Pat. No. 8,358,615; which is(are) hereby incorporated by reference.

FIELD OF THE DISCLOSURE

The present patent disclosure generally relates to wirelesscommunication devices, examples of which include mobile handheld devicessuch as pagers, cellular phones, personal digital assistants (PDAs),smartphones, wirelessly enabled portable computers, and the like. Moreparticularly, and not by way of any limitation, the present patentdisclosure is directed to providing radiation power level control withrespect to a wireless communication device.

BACKGROUND

For many years the general public has been concerned about the possiblehealth effects of exposure to electromagnetic radio frequency (RF)radiation. Although research is ongoing and there appears to be noscientific consensus on the subject at this time, there have beenconcerns expressed that high levels of radiation fields may cause avariety of physical effects on the human body. With the dramaticincrease in public use of wireless communication devices, andparticularly mobile telephones, it has become prudent to consider thatthese products do not expose their users to levels of radiation that maybe excessive. At the frequencies at which most of these devices operate,the known physiological effects center around tissue heating. A measureof this heating effect is known as Specific Absorption Rate (SAR), whichis defined as the time derivative of the incremental energy (dW)absorbed by or dissipated in an incremental mass (dm) contained in avolume (dV) of a given density (ρ).

As part of worldwide efforts to legislate on consumer health and safetyaspects, many regulatory bodies in the United States of America as wellas abroad (e.g., governmental agencies such as the FederalCommunications Commission or FCC in the United States) now requireproducts that are placed on the market to meet SAR limits. Measurementof SAR has therefore become mandatory for companies that make suchproducts.

The basis for US requirements may be found in ANSI/IEEE C95.1 “SafetyLevels with Respect to Human Exposure to Radio Frequency ElectromagneticFields, 3 kHz to 300 GHz” which establishes exposure limits, andANSI/IEEE C95.3 “Recommended Practice for the Measurement of PotentiallyHazardous Electromagnetic Fields—RF and Microwave”. These standards arereflected in the current FCC requirements found in 47 CFR §2.1091 and2.1093. OET Supplement C 01:01 “Evaluating Compliance with FCCGuidelines for Human Exposure to Radiofrequency Electromagnetic Fields”gives guidance on the application of the FCC rules. (OET is the FCC'sOffice of Engineering and Technology). The FCC rules for evaluatingportable devices for RF exposure compliance are contained in 47 CFR§2.1093. For these purposes, a portable device is defined as atransmitting device designed to be used with any part of its radiatingstructure in direct contact with the user's body or within 20centimeters of the body of a user or bystanders under normal operatingconditions. For distances greater than 20 centimeters, exposureevaluation is determined by the maximum permissible exposure limits(MPE) provided in OET 65.

For instance, the FCC limit for exposure from cellular telephones is aSAR level of 1.6 watts per kilogram (1.6 W/kg) averaged over 1 gram oftissue. The SAR scan test is usually 6 minutes for most technologiesexcept for those operating in the range of 5 GHz to 6 GHz. Tests fortechnologies operating at such higher RF levels typically require asmaller step size for the necessary volume scan, thereby giving rise toa testing time of about 15 minutes.

Because of the ever-improving advances in the wireless communicationtechnologies, the regulations for limiting electromagnetic RF radiationare being continuously updated as well. With the change in usage ofmobile phones and the concomitant advent of newer technologies, furtherregulatory changes are anticipated. Currently, with the goal of reducingthe likelihood that cellular phone transmissions of electromagneticradiation will cause harmful effects in users, government regulations inseveral countries limit the maximum power level with which the cellularphones can radiate. This limitation is tied to a SAR threshold. However,the SAR level for a wireless device is determined in a common, specifiedmanner for all cellular phones, and if a proposed phone design exceedsthe SAR threshold, the design of at least part of the RF transmittersystem must be adjusted. These adjustments, if not handled well, can bedetrimental to the efficiency and performance of the phone's RF systems.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the embodiments of the present patentdisclosure may be had by reference to the following Detailed Descriptionwhen taken in conjunction with the accompanying drawings wherein:

FIG. 1 depicts a block diagram of a wireless user equipment (UE) devicewherein transmission power levels may be controlled in accordance withan embodiment of the present patent application;

FIG. 2 depicts a block diagram of an embodiment of a radiation powerlevel control system for a wireless UE device for purposes of thepresent patent application;

FIG. 3 depicts an illustrative example of a tracked power level/datahistory database representation according to one embodiment;

FIG. 4 is a flowchart of an example radiation power level control schemeof the present patent application;

FIG. 5A is a flowchart of an example radiation power level controlmethod in additional detail according to one embodiment;

FIG. 5B is a flowchart of another example radiation power level controlmethod according to a further embodiment of the present patentapplication;

FIG. 6 is a flowchart of another example method of the present patentapplication;

FIG. 7 depicts a block diagram of an example wireless UE device inadditional detail according to one embodiment of the present patentapplication; and

FIG. 8 is an example network environment wherein an embodiment of aradiation power level control scheme may be implemented by one or moreelements of the network environment.

DETAILED DESCRIPTION OF THE DRAWINGS

The present patent disclosure is broadly directed to a radiation powerlevel control scheme based on a tracked radiation history of a wirelessUE device. A comprehensive approach is provided based on device usage aswell as communication of control signals resulting from dynamictransmission power level measurements, SAR determinations, and the like,to suitable network infrastructure elements.

In one aspect, an embodiment of a radiation power level control methodfor a wireless UE device is disclosed. The claimed method comprises oneor more of the following: determining a time-average transmission powerlevel; comparing the time-average transmission power level with a firsttime-averaged transmission power limit threshold, the firsttime-averaged transmission power limit threshold having a value thatdepends on a transmission power level history for the UE device; andresponsive to the time-average transmission power level meeting orexceeding the first time-averaged transmission power limit threshold,reducing a transmission power level of the UE device.

In a related aspect, an embodiment of a wireless UE device is disclosed.The claimed wireless UE device comprises one or more of the following: acomponent configured to determine a time-average transmission powerlevel associated with the wireless UE device; a component configured tocompare the time-average transmission power level with a firsttime-averaged transmission power limit threshold, the firsttime-averaged transmission power limit threshold having a value thatdepends on a transmission power history for the UE device; and acomponent, operable responsive to the average transmission power levelmeeting or exceeding the first time-averaged transmission power limitthreshold, configured to reduce a transmission power level of the UEdevice. In one implementation, the wireless UE device may also include astorage element for storing the transmission power level historyassociated with the wireless UE device, wherein the transmission powerlevel history comprises data tracked over a time window relative to oneor more variables, wherein the time window may be fixed, variable, or asliding window, for example.

In a further aspect, another embodiment of a radiation power levelcontrol method for a wireless UE device is disclosed. The claimed methodcomprises one or more of the following: determining that a currenttransmission event involving the wireless UE device occurred within apredetermined duration from a last transmission event; responsive to thedetermining, using a power data history associated with the wireless UEdevice in determining one or more Specific Absorption Rate (SAR) valuesduring the current transmission event, the power data history comprisingdata tracked over a time window (which can be a sliding or moving timewindow, fixed or variable, in one implementation) relative to one ormore variables; if the current transmission event occurred outside thepredetermined duration from the last transmission event, resetting thepower data history and using the reset power data history in determiningthe one or more SAR values during the current transmission event; and ifat least one of the one or more SAR values exceeds a threshold,effectuating a control action relative to the current transmissionevent, the control action including at least reducing a transmissionpower level radiating from at least one radio frequency (RF) antenna ofthe wireless UE device.

In a still further embodiment, a wireless UE device is disclosed thatcomprises one or more of the following: a storage element for storing apower data history associated with the wireless UE device, the powerdata history comprising data tracked over a time window (e.g., a slidingwindow) relative to one or more variables; a component configured todetermine one or more SAR values during a current transmission eventusing the power data history, if the current transmission eventinvolving the wireless UE device occurred within a predeterminedduration from a last transmission event; a component configured to resetthe power data history if the current transmission event occurredoutside the predetermined duration from the last transmission event, andto determine the one or more SAR values during the current transmissionevent using the reset power data history; a component configured toeffectuate a control action relative to the current transmission event,if at least one of the one or more SAR values exceeds a threshold,wherein the control action includes at least reducing a transmissionpower level radiating from at least one RF antenna of the wireless UEdevice. Generally speaking, an element may be “configured to” perform afunction if the element is capable of performing or otherwisestructurally arranged to perform that function.

In a further aspect, an embodiment of radiation power level controlsystem for controlling transmission power level of a wireless UE deviceis disclosed. The claimed control system comprises one or more of thefollowing: a tracking component for maintaining a history of power datafor the wireless UE device, the power data comprising data tracked overa time window (e.g., a sliding window) relative to one or more variableson a per transmission event basis; a SAR determining module fordetermining one or more SAR values for the wireless UE device during acurrent transmission event involving the wireless UE device, wherein theSAR determining module is configured to use the history of power data ifthe current transmission event occurred within a predetermined durationfrom a last transmission event involving the wireless UE device; and anadjustment module configured to facilitate adjusting a transmit powerlevel of the wireless UE device if at least one of the one or more SARvalues exceeds a threshold.

Embodiments of systems, methods, and associated tangiblecomputer-readable media having instructions and tangible computerprogram products relating to a radiation power level control scheme ofthe present patent disclosure will now be described with reference tovarious examples of how the embodiments can be made and used. Likereference numerals are used throughout the description and several viewsof the drawings to indicate like or corresponding parts to the extentfeasible, wherein the various elements may not necessarily be drawn toscale. Referring now to the drawings, and more particularly to FIG. 1,depicted therein is a block diagram of an example wireless UE device 100wherein transmission power may be controlled in accordance with anembodiment of the present patent application. By way of illustration,the wireless UE device 100 may be any cellular phone, mobilecommunications device, smart phone, PDA, wirelessly enabled portablecomputer, pager, and the like. The wireless UE device 100 may beprovided with one or more appropriate transceiver and antennaarrangements, each of which may be adapted to operate in a certainfrequency band (i.e., operating frequency or wavelength) depending onthe radio access technologies of the communications networks such as,without limitation, Global System for Mobile Communications (GSM)networks, Enhanced Data Rates for GSM Evolution (EDGE) networks,Integrated Digital Enhanced Networks (IDEN), Code Division MultipleAccess (CDMA) networks, Universal Mobile Telecommunications System(UMTS) networks, any 2nd- 2.5- 3rd- or subsequent Generation networks,Long Term Evolution (LTE) networks, or wireless networks employingstandards such as Institute of Electrical and Electronics Engineers(IEEE) standards, like IEEE 802.11a/b/g/n standards or other relatedstandards such as HiperLan standard, HiperLan II standard, Wi-Maxstandard, OpenAir standard, and Bluetooth standard, as well as anysatellite-based communications technology such as GPS. Accordingly, thewireless UE device 100 may operate in one or more modes, bands, or radiotechnologies, and may be adapted to communicate using circuit-switchednetworks (CSNs), packet-switched networks (PSNs), or a combination. Thewireless UE 100 may therefore comprise a multi-mode wirelesscommunication device which is not intended to be limited by any of theexemplary types of radio technologies, transceiver circuitry orradiation elements (i.e., antenna technologies, etc.) exemplifiedherein.

In FIG. 1, the wireless device 100 is illustrated with a plurality oftransceivers 106-1 through 106-N, each having an associated radiationelement (i.e., antenna) 108-1 through 108-N (i.e., a first antenna, asecond antenna, etc.) for transmitting and receiving RF signals carryinginformation. While each transceiver is shown as being coupled to acorresponding antenna or radiation element, in other embodiments two ormore transceivers may share a common antenna. Additionally, eachtransceiver may be associated with suitable power amplification andbaseband controller circuitry 104-1 through 104-N, which may alsoinclude Layer 1 software/firmware functionality. In alternativeembodiments, the power amplification and baseband controller circuitriesmay be implemented as a single entity, for example, a digital signalprocessor (DSP) (not explicitly shown in FIG. 1).

The wireless UE device 100 also includes a controller 102 configured tocontrol the output power of the transmitters accordingly to one or moreembodiments set forth hereinbelow in further detail. More generally, inembodiments where there are multiple transceivers, the controller maycontrol the output power of one or more transmitters, or any subsetthereof, depending on one or more radiation power control scenarios andassociated control logic exemplified in the present patent application.Those skilled in the art will recognize that the controller may beimplemented as part of one or more processors, for example, a commonDSP, or it may be a separate control entity. For instance, the controlfunctionality may be implemented by a programmably controlled processorusing software stored in memory. Moreover, the control functionality maybe effectuated under local control (i.e., based on executable controllogic resident on the wireless UE device), or under control from asuitable network infrastructure element (e.g., a network node such as abase station or some other network node executing suitable service logicconfigured to receive information indicative of transmission radiationpower levels of one or more wireless devices and operate thereon togenerate control signals), or based on any combination thereof.

FIG. 2 depicts a block diagram of an embodiment of a radiation powerlevel control system 200 for a wireless UE device in accordance with theteachings of the present patent application. A power level and relateddata history tracking module or subsystem 202 is configured to monitor,record, store, update (e.g., bring data up to date or verify the data ascurrent, which may or may not involve changing any data), and/orotherwise maintain data relating to one or more variables relevant topower level computations. A Specific Absorption Rate (SAR) determiningmodule 206 is provided for determining one or more SAR values for awireless UE device, wherein the SAR determining module is configured touse, for example, the historical power level data, duration of theactivity in addition to other related data maintained by the powerlevel/data history tracking module 202 depending at least in part on howthe calls or data transmission events involving the UE device are spacedin time. It will be recognized that a wireless UE device may engage inseveral types of communication activities, e.g., voice calls, videocalls, data sessions, data downloads or transmissions, as well asvarious uplink communications to the network, each having variabledurations and power level transmission characteristics. For purposes ofthe present patent application, accordingly, the term “transmissionevent” is intended to cover all such communication activities in anon-limiting way. An adjustment module 204 is configured to facilitateadjusting a transmit power level of the wireless UE device based on theSAR information provided by the SAR determining module 206. Theadjustment module 204 may also be configured to communicate with thepower level/data history tracking module 202 for updating or otherwisemanipulating the power data therein. The history tracking subsystem 202can provide current SAR values computed from the current transmissionevent and can also include future SAR values calculated fromextrapolated values using the SAR values from previous events.Accordingly, by way of illustration, the data (which includes both powerlevel data as well as transmission event time data) may be updated suchthat the “updated” data may include any or all past, current, and futureextrapolated data. Additionally, a notification module 208 is configuredto provide a notification message to the user, to the wireless UEdevice, to a network node, or any combination thereof, wherein thenotification message may be generated at least depending on the SARmeasurement information provided by the SAR determining module 206 withrespect to an ongoing transmission event in which the wireless UE deviceis currently engaged. The functionality of the adjustment module 204and/or the notification module 208 may also include, inter alia,generating appropriate control signals to control, change or otherwisemanipulate a modulation and coding scheme (MCS) used by the wireless UEdevice in its current transmission event.

It should be recognized that the foregoing radiation power controlscheme may be implemented entirely on a wireless UE device (i.e., localcontrol), in a network node (i.e., remote control), or in a combinationthereof, wherein one or more components of the radiation power controlscheme may be realized in a serving network. As used herein, a componentmay comprise one or more tangible elements, such as a sensor orprocessor, and may comprise program instructions that may configure theelements to perform one or more operations. For example, a powerlevel/data history monitoring system or subsystem may be deployed at abase station for maintaining various data relevant to power level,transmission event time information and SAR computations with respect tothe wireless UE devices served by the base station. Associated therewithmay also be a SAR determining module as well as an adjustment module,which can determine SAR values for each UE device and send appropriatecontrol signals thereto (e.g., to reduce the transmit power level,change the MCS, to provide user notifications, etc.). In an alternativearrangement, such functionality may be located at a differenthierarchical location in the network, e.g., a centralized network nodethat receives or otherwise obtains appropriate information signalsindicating transmission characteristics of ongoing events engaged byvarious wireless devices. One or more such alternative arrangements willbe set forth in additional detail hereinbelow.

Regardless of where the example radiation power level control scheme isimplemented, the power level/data history tracking module 202 of thescheme may be configured to monitor data over a time window that may befixed or variable, and may be configured to take into account, interalia, various usage modes associated with a wireless UE device,historical data relating to how the transmission events are distributedover time, durations and types of the transmission events, and the like,such that a SAR determining module can intelligently incorporate suchdata into computing or otherwise determining a more realistic SAR valuefor a wireless UE device during a transmission event. By incorporatingor taking in account various parameters, an adaptive power level controlscheme may be implemented by varying the durations of a sliding timewindow depending on, e.g., usage modes, transmission event types, etc.Examples of such parameters may include determining that transmissionevents that are of same type (e.g., voice calls, data transmissions, orthe like) and sufficiently close to one another in time may affect theSAR value determinations, or determining that some transmission eventsare sufficiently separated in time and/or of different type may not soaffect the SAR value determinations, Additionally, SAR values determinedby taking into account the data tracked over a course of time areexpected to be more accurate, and thus help achieve regulatorycompliance in a more meaningful and faithful manner.

FIG. 3 depicts an example of a database representation 300 of a trackedpower level and transmission event time data history according to oneembodiment, which is illustrative of a database that may be maintainedwithin a wireless UE device, at a network node or may be distributed inany fashion. A variety of transmission event types involving a wirelessdevice, such as, e.g., voice calls, data sessions, uplinkcommunications, etc., essentially any event that may have an impact onthe transmit power level of the wireless UE device and therefore mayhave an effect on the SAR to which the user may be exposed, may betracked for developing a fairly comprehensive power data history forpurposes of the present patent application. Reference numerals 302-1through 302-N refer to N types of such transmission events that mayencompass the full range of communication activities by a wireless UEdevice. A number of device usage modes 304-1 through 304-M may beincluded for tracking mode-specific power data histories. An exampleusage mode may be where the wireless UE device is normally positionednear a user's ear for making a phone call. Another example usage modemay be where the wireless UE device is placed in a holster that ispositioned adjacent to the user's body. Another example usage mode iswhere the wireless UE device is placed in a bag, a purse, or a holster,or some container, which may be positioned near the user or at a pointaway from the user. A still further usage mode is where the wireless UEdevice is placed in a speakerphone mode and is positioned away from theuser's body and/or placed on a desk, for example. It should be apparentthat the usage modes set forth in the foregoing non-limiting list aremerely illustrative and any number of usage modes may be realizeddepending on a particular implementation for purposes of the presentpatent application.

Various techniques and schemes, both device-based and network-based, maybe used for determining and tracking device usage. For example,components such as accelerometers, motion sensors, temperature sensors,position/location sensors, etc. may be provided in a wireless UE deviceto determine if the device is on a flat surface such as a desk, near theuser's body, in a holster, in a speakerphone mode, or near the user'sear, etc., while engaged in a transmission event. When a transmissionevent takes place in multiple usage modes, it is therefore possible toseparately track the usage in the different modes used and accordinglyupdate the power data history. For example, if the usage is initially byplacing the device near the user's ear and then switched to speakerphonemode, the history tracking system is configured to save the history forthe ear usage mode and the speakerphone usage mode as needed.Additionally, although a number of usage modes are illustrated in FIG.3, one implementation of the database representation and associatedradiation power level control scheme may not make or require suchdistinctions and therefore treat all usage modes as the same forpurposes of SAR determination.

Regardless of how many transmission event types and/or usage modes arecomprehended, the database representation 300 may be populated with, foreach transmission type and usage mode, data 306 relating to variablesincluding but not limited to, e.g., (i) time elapsed since the lasttransmission event, (ii) duration of the last transmission event, (iii)nominal antenna SAR values (which can be operating frequency-dependentand may be programmed into the wireless UE device or downloaded), (iv)last power level (total or peak) and (v) last average power level, andother related parametrics. Such data 306 may be maintained for a timewindow, e.g., a sliding or moving time window, may cumulatively bereferred to herein as “power data history”. Since SAR determinationsapplicable for one usage mode and/or transmission event type may not berelevant to other usage modes and/or transmission event types, a morerealistic and accurate SAR measurement process may be implemented bytracking the mode-specific and event-specific data as set forthhereinabove.

FIG. 4 is a flowchart of an example radiation power level control scheme400 of the present patent application according to one embodiment. Atblock 402, a power data history tracking module, component, system orsubsystem is implemented for monitoring, recording, updating andmaintaining appropriate power level/data over a period of time as setforth above. As described previously, a configurable time window, eitherfixed or variable, may be imposed so that only more recent power datahistory is utilized for SAR determinations. However, the entirehistorical record of the cumulative power data may be warehoused orotherwise maintained either locally on the device or remotely at anetwork node. When the wireless UE device commences a transmission event(designated as a current transmission event), a determination is madewhether or not the current transmission event is within a predeterminedduration from a last transmission event (block 404). In general, aquantity or element in a step of a method of the present application is“predetermined” when it is determined at any time before the step in themethod is reached. With this in mind, if the current transmission eventis within a predetermined duration, responsive to such determining, thepower data history associated with the wireless UE device is used inmeasuring, computing or otherwise determining (including, e.g., using alook-up table that is locally stored on the UE device or otherwise) oneor more SAR values during the current transmission event, wherein thepower data history comprises data tracked over a time window (block404). If the current transmission event occurs or commences outside thepredetermined duration from the last transmission event, the power datahistory is disregarded for determining the SAR computations (block 406).In one implementation, the power data history tracked over the timewindow may be reset or reinitialized to certain predetermined defaultdata, including, e.g., zeroing out the data tracked over the timewindow. Thereafter, a further determination is made if one or more SARvalues determined—either incorporating the tracked power data (as inblock 404) or not (as in block 406)-exceeds a threshold value (e.g.,based on SAR limits imposed by regulatory bodies, marketing or industryconsortia, or limits imposed internally by the manufacturer orconfigured by the user, and the like). If so, a control action may beeffectuated relative to the ongoing current transmission event, forexample, reducing a transmission power level radiating from at least oneRF antenna for the wireless UE device, providing a notification orindication to the user of the wireless UE device that the SAR level hasexceeded, changing the MCS (including the number of transmission slots,for instance) used by the wireless UE device, terminating thetransmission event, providing a notification or indication to a servingnode, e.g., a base station or an enhanced Node B (if the process isexecuted on the wireless UE device), providing a control signal ornotification to the wireless UE device (if the process is executed at anetwork node), delaying the transmission event in the case ofdelay-tolerant transmission, and the like (block 408). Those skilled inthe art should recognize that this list of control actions isnon-limiting and one or more actions may take place at the wireless UEdevice while another set of control actions may take place if the powerlevel control process is executed elsewhere. Additionally, two or morecontrol actions (i.e., a composite control action) may take place insome implementations.

FIG. 5A is a flowchart of an example radiation power level controlmethod 500A that amplifies the foregoing scheme with additional detailaccording to one embodiment. When a new current transmission eventinvolving the UE device takes place (block 501), suitable power datahistory is retrieved from a history tracking system, which includes,inter alia, time elapsed since the last transmission event (block 502).At block 504, a determination is made if the duration between thecurrent transmission event and the last transmission event is within aminimum time interval allowed between transmission events. As alluded topreviously, the minimum time interval may be configured, variable,fixed, or otherwise provisioned for a particular wireless UE device andmay be adaptive based on transmission event types and/or usage modes. Ifthe duration is within the minimum time interval, the power dataretrieved from the history tracking system is used for computing orrecomputing SAR values, in addition to updating the history trackingsystem with the current power data (block 508). On the other hand, ifthe duration between the last and current events is not within theminimum time interval, the power data history is reset (block 506). Asthe current transmission event provisioned with initial transmit powerlevels, transmission MCS and other transmission parametrics commences orcontinues to take place, the power data history tracking systemcontinues to monitor the current transmission event time, power levels,and other related information (block 510). At block 512, a decision ismade if there is a change in the power level during the transmissionevent (e.g., relative to a tracked power level value, a predeterminedlimit, etc.). If so, a SAR determination module computes, recomputes,measures, or otherwise determines a new SAR value, which can be based onmathematical formula or a look-up table, etc. (block 518). Where amulti-mode transmission event is taking place, i.e., with more than onetransceiver plus antenna combination being effective, the new SAR valuemay be a summation of the SAR components for each transceiver plusantenna combination. In one embodiment, a new SAR value may be computedas a function of nominal SAR (which itself is dependent on the operatingfrequency and may be determined during the design of a particularwireless UE device), nominal power level, and nominal transmissionconfiguration (including a nominal number of transmission slots andassociated modulation/coding scheme, for instance) and other relatedparametrics. Additional details regarding transmission power levelmeasurements, SAR computations and MCS adjustment schemes may be foundin the following co-pending, commonly assigned U.S. patent applications:(i) “TRANSMISSION CONTROL FOR A SPECIFIC ABSORPTION RATE COMPLIANTCOMMUNICATION DEVICE”, application Ser. No. 12/536,339; filed Aug. 5,2009; and (ii) “MODULATION AND CODING SCHEME SELECTION METHOD FOR ASPECIFIC ABSORPTION RATE COMPLIANT COMMUNICATION DEVICE”, applicationSer. No. 12/722,362; filed Mar. 10, 2010, now issued as U.S. Pat. No.8,358,615; which is (are) hereby incorporated by reference.

Continuing to refer to the flowchart of FIG. 5, if there is no change inthe power level, a further determination is made (block 514) withrespect to duration of the ongoing transmission event. If thetransmission event exceeds a predetermined time limit (e.g., a user- ormanufacturer- or network-configurable threshold, which again can bevariable or fixed depending on transmission event type and usage mode),the SAR determination module is invoked and executed as described above(block 518). Otherwise, if the current transmission event has not beencompleted (block 515), the control flow returns to monitoring the powerlevels (total, peak, average, or any combination) and other transmissionparametrics by the power data history tracking system at block 510.Thus, it should be realized that in this embodiment both transmit powerlevels and elapsed time during the transmission event are monitored andnew SAR values are appropriately determined until the currenttransmission event is terminated (block 516).

As the SAR determination module continues to compute or re-compute thenew SAR values as necessary (block 518), for each new SAR value adetermination is made if the new SAR value exceeds a threshold (block520). As described previously, the SAR thresholds may be configured in anumber of ways, stored locally or on the network, and may also be set upbased on transmission event types and/or usage modes, device type,antenna placement, etc. Additionally, the SAR thresholds may also beconfigured based on individual users since different users may havedifferent radiation energy tolerances (e.g., depending on gender, bodytype and/or health condition, pregnancy, and the like). Regardless ofhow the SAR threshold values are set up, if a computed/recomputed newSAR value does not exceed the applicable threshold, the control flowreturns to monitoring the power levels and other transmissionparametrics by the power data history tracking system at block 510 asbefore. However, if a new SAR value exceeds the threshold, transmitpower levels may be reduced, MCS may be changed (e.g., from a scheme ofquadrature phase shift keying (QPSK) with a suitable coding rate (forinstance, ⅓, ½ or ⅔) to a scheme of quadrature amplitude modulation(QAM) at coding rates of ½, ⅔, or so on), as set forth in block 522. Inaddition, as previously described, additional control actions, signalsand notifications may also take place, including termination of thetransmission event itself (block 516). In a further variation, the SARthreshold values may be implemented with suitable lower and upper guardbands such that when a “floor” is reached an advance warning may beprovided and extrapolated SAR may re computed as part of thefunctionality of blocks 518 and 520. Also, with different guard bandsimplemented, different levels of control actions and notifications maybe generated in accordance with the teachings of the present patentdisclosure.

FIG. 5B is a flowchart of another example radiation power level controlmethod 500B for a UE device in a further embodiment of the presentpatent application that involves using a tracked power level andtransmission event time history. Upon commencing a transmission eventinvolving the UE device (block 501), a time-average transmission powerlevel (or time-average power level, for short) is determined over a timewindow, which may be fixed or variable as previously described (block552). In general, a time-average transmission power represents anaverage of transmission power measured over the time window. The averagemay be, but need not necessarily be, the arithmetic mean. The averagemay also comprise one or more values that represent the generalsignificance of a set of transmission power values, such as a weightedaverage or a median or an approximation of the arithmetic mean. Thetime-average transmission power level is compared against a thresholdvalue, e.g., a first time-averaged transmission power limit threshold,wherein the first time-averaged transmission power limit threshold has avalue that depends on a transmission power history for the UE device(block 554). For example, but not by way of limitation, an illustrativetransmission power history may comprise, a tracked power level andtransmission event time data history set forth hereinabove. Thereafter,responsive to the time-average transmission power level meeting orexceeding the first time-averaged transmission power limit threshold, acontrol action, e.g., reducing a transmission power level of the UEdevice with respect to the ongoing transmission event, may beeffectuated (block 556). As before, any threshold values relating totransmission power levels, time-averaged, instantaneous, peak, orotherwise, may be stored in the UE device, at a network node, and may beconfigurable. In one specific implementation involving a manipulation ofthe transmission power level, reducing the transmission power level maycomprise reducing a number of transmission time slots used by the UEdevice. Additionally, optionally, or alternatively, the feature ofreducing the transmission power level may also comprise retaining,within each of the reduced number of transmission time slots, a timeslot transmission power level that is consistent with a time slottransmission power level used by the UE device prior to the reducing. Inanother implementation, reducing the transmission power level of the UEdevice may comprise reducing a frame-average transmission power levelused by the UE device, wherein the frame-average transmission powerlevel is averaged over a single transmission frame comprising multipletime slots and the time-average transmission power level is averagedover multiple transmission frames. In a still further implementation,reducing the transmission power level of the UE device may compriseturning off one or more transmission functions, or turning off the UEdevice completely. For example, additional details regardingtransmission power level measurements and associated adjustment schemesmay be found in one or more of the co-pending, commonly assigned U.S.patent applications incorporated by reference hereinabove.

Where multiple types of communication processes take place in an ongoingcurrent transmission event, another variation may involve retaining afirst communication process and suspending a second communicationprocess, in conjunction with (or in some cases in alternative to)reducing the transmission power level. For instance, as alluded topreviously, the first communication process may comprise a voice callwhereas the second communication process comprises a data file transfer,or vice versa. Where a composite control action may be involved (e.g.,effectuating two or more control actions relative to a radiation powerlevel control method for the UE device), one or more of thecommunication processes of the transmission event may be suspended,along with providing a notification to a user. As described previously,additional variations of composite control actions (e.g., two or morecontrol actions being effected in conjunction) may include sending amessage to a serving network node, e.g., an enhanced/evolved Node B(eNodeB or eNB) in an LTE network, a conventional base station, or someother network node in a core or service network, wherein the message isconfigured to indicate a change in one or more parameters relating tothe transmission event, e.g., the transmission power level of the UEdevice.

Continuing to refer to the embodiment of FIG. 5B, another implementationmay involve, in conjunction with reducing the UE device's transmissionpower level, changing a modulation and coding scheme (MCS) from a firstMCS to a second MCS, wherein the second MCS may be configured to providea lower expected bit-error-rate (BER) than a BER for the first MCS atthe reduced transmission power level. As a further variation, theradiation power level control method 500B may also include the acts of:(i) comparing the time-average transmission power level with a secondtime-averaged transmission power limit threshold, the secondtime-averaged transmission power limit threshold having a lower valuethan the first time-averaged transmission power limit threshold; and(ii) responsive to the time-average transmission power level meeting orfalling below the second time-averaged transmission power limitthreshold, increasing a transmission power level of the UE device. Inthis variation, increasing the transmission power level may compriseincreasing a number of transmission time slots used by the UE device.Also, in conjunction with increasing the transmission power level, theMCS used by the UE device may be changed from a first MCS to a secondMCS, wherein the second MCS provides a higher data rate than a data ratefor the first MCS.

In a still further variation, the radiation power level control method500B may also include one or more of the following acts: (i) determiningwhether a current transmission event occurs within a predeterminedduration window from a prior transmission event; (ii) responsive todetermining that the current transmission event does occur within thepredetermined duration window, including at least a portion of atransmission power level history of the prior transmission event in thedetermination of average transmission power level; and (iii) responsiveto determining that the current transmission event does not occur withinthe predetermined duration window, excluding the transmission powerlevel history of the prior transmission event from the determinedaverage transmission power level. Similar to the features previouslydescribed with respect to some of the other embodiments, the radiationpower level control method 500B may also include tracking at least oneradiation history parameter selected from the list consisting of: a timeelapsed since a prior transmission event, a duration of the priortransmission event, a final power level (e.g., a last power level,either peak or average, etc.) of the prior transmission event, atime-average power level of the prior transmission event, and one ormore antenna SAR values of the UE device (if provided with multipleantennas as exemplified in FIG. 1, for instance).

Those skilled in the art should recognize that because of the diversearray of information relating to power levels, transmission event timingparametrics, etc., that is tracked as part of the radiation history of aUE device, several additional features can also be implemented withrespect to the radiation power level control method 500B. In onevariation where the UE device is provided with multiple antennas, someof the control actions may involve determining whether changingtransmission from a first antenna to a second antenna will reduce a SARexposure of a user of the UE device (e.g., amount of radiation exposedto the user); and, additionally or optionally, responsive to determiningthat changing transmission from the first antenna to the second antennawill reduce a SAR exposure, ceasing transmission from the first antennaand transmitting with the second antenna and/or providing a suitablenotification in connection therewith. Where a private call mode isemployed with respect to the transmission event, the radiation powerlevel control method 500B may further include, for example, the acts ofdetermining whether the UE device is in use according to a private voicecall mode (e.g., without limitation, the calling party's number is keptprivate and may not be identified by caller ID); and responsive todetermining that the UE device is not in use according to a privatevoice call mode, suspending comparison of the time-average transmissionpower level with a first time-averaged transmission power limitthreshold. In such an implementation, additional refinements mayinclude, for example, the determination that the UE device is in useaccording to a private call mode may be based on whether the UE deviceis holstered, whether the UE device is in a speakerphone mode, and thelike. The speakerphone mode may be determined based on, e.g., detectingthat the speakerphone speaker is activated, an accelerometer indicates ahorizontal orientation of the UE device (e.g., without limitation, anorientation that is determined as horizontal with respect to an axis ofthe device), or both.

In another embodiment involving the UE device being in use in a privatevoice call mode, a determination that the UE device is in the privatevoice call mode may be made based on whether the UE device is in useaccording to a data entry mode. In such an implementation, additionalrefinements may include, for example, the determination that the UEdevice is in use according to a data entry mode may be based on whetherthe UE device's keyboard is registering key presses at a rate that isconsistent with typing by a user, whether an accelerometer indicates adata entry orientation of the UE device, or both. Where the UE device isdetermined to be not in use according to a private call mode, acomparison of the time-average transmission power level may be made withan alternative power limit threshold that is different than the firsttime-averaged transmission power limit threshold as set forth in FIG.5B. As described in detail previously in reference to the otherembodiments, one or more features relating to the embodiment of FIG. 5Bmay be performed or otherwise implemented on the UE device, or at anetwork node, or in any combination thereof.

Referring now to FIG. 6, depicted therein is a flowchart of anotherexample method 600 of the present patent application for use with one ormore variations of an adaptive radiation power level control schemedescribed hereinabove. When a transmission event involving a wireless UEdevice commences (block 601), a determination may be made as to whetherthe transmission event is in a mode for which SAR measurements arerelevant. If the transmission event or its usage mode is such that theSAR measurements are not implicated, there is no need to launch a powerdata history tracking module and monitor and update the power datahistory. The process flow of the adaptive radiation power level controlcan exit and the transmission event can continue in conventional manner(block 606). Otherwise, the power data history tracking module may belaunched (block 604), whereupon tracked power data may be retrieved ifnecessary. Transmission power levels, SAR values, etc. may be determinedand appropriate adjustment control and associated control actions may betaken (block 608) as described in detail above. If the usage modechanges during the transmission event, that is, for example, where thetransmission event may comprise multiple communication processes, afurther determination may be made (block 610) whether to continuetracking the power level data and determine SAR values accordingly. Ifso, the acts of block 608 may continue to be taken. Otherwise, the powerhistory data may be updated, if needed, upon the transition of acommunication process or usage mode, and the process flow may exit asnecessary (block 606).

FIG. 7 depicts a block diagram of an example wireless UE device 700according to one embodiment of the present patent application. It shouldbe understood that the wireless UE device 700 may be another embodimentof a wireless UE device such as the device 100 with additionalstructural and functional elements shown. Wireless UE device 700 may beprovided with a communication subsystem 704 that includes an antennaassembly 708 and suitable transceiver circuits 706 whose power outputlevels can be controlled according to one or more embodiments of thepresent disclosure. A microprocessor 702 providing for the overallcontrol of the device 700 is operably coupled to the communicationsubsystem 704, which can operate with various access technologies,operating bands/frequencies and networks (for example, to effectuatemulti-mode communications in voice, data, media, or any combinationthereof). As will be apparent to those skilled in the field ofcommunications, the particular design of the communication module 704may be dependent upon the communications network(s) with which thedevice is intended to operate, e.g., as exemplified by infrastructureelements 799 and 797. Further, the antenna assembly 708 may compriseradiation elements that may be realized in any known or heretoforeunknown elements such as, e.g., a patch antenna, an inverted F antenna(IFA) strip, a modified inverted F antenna (MIFA) strip, a planarinverted F antenna (PIFA) strip, and the like, in any shape, size andform factor.

Microprocessor 702 also interfaces with additional device subsystemssuch as auxiliary input/output (I/O) 718, serial port 720, display 722,keyboard 724, speaker 726, microphone 728, random access memory (RAM)730, other communications facilities 732, which may include for examplea short-range communications subsystem, and any other device subsystemsgenerally labeled as reference numeral 733. Example additional devicesubsystems may include accelerometers, motion sensors, temperaturesensors, and the like. To support access as well as authentication andkey generation, a SIM/USIM interface 734 (also generalized as aRemovable User Identity Module (RUIM) interface) is also provided incommunication with the microprocessor 702 and a UICC 731 having suitableSIM/USIM applications. As noted above with respect to FIG. 2, anotification module 208 may be configured to provide a notificationmessage to, for example, a user or a network node, depending on wherethe notification module is implemented. The notification message may beprovided to a user by way of the display 722 or speaker 726, forexample. The notification message may be provided to a network node viatransceiver circuits 706, serial port 720 or other communicationsfacilities 732, for example. In some embodiments, microprocessor 702 canbe configured to carry out, in conjunction with one or more subsystemsof the UE device 700 described herein, one or more operations ofradiation power level control system 200 shown in FIG. 2, in addition toone or more features of the embodiments of FIGS. 5A-5B and FIG. 6.

Operating system software and other system software may be embodied in apersistent storage module 735 (i.e., non-volatile storage) which may beimplemented using Flash memory or another appropriate memory. In oneimplementation, persistent storage module 735 may be segregated intodifferent areas, e.g., transport stack 745, storage area for computerprograms 736, as well as data storage regions such as device state 737,address book 739, other personal information manager (PIM) data 741, andother data storage areas generally labeled as reference numeral 743.Additionally, the persistent memory may include appropriatesoftware/firmware 750 necessary to effectuate transmission power levelmeasurement and computations, SAR determinations, power level adjustmentcontrol, power data history tracking and associated database(s), inconjunction with one or more subsystems set forth herein under controlof the microprocessor 702 or specialized DSP circuitry. Poweredcomponents may receive power from any power source (not shown in FIG.7). The power source may be, for example, a battery, but the powersource may also include a connection to power source external towireless UE device 700, such as a charger.

FIG. 8 is an example network environment 800 wherein an embodiment of aradiation power level control scheme may be implemented by one or moreelements of the network environment. A mobile communications device(MCD) 802 may be representative of a multi-mode wireless UE device, andcomprises a power data history tracking logic and adjustment controlmodule 803 that may be implemented in hardware, software, firmware or inany combination, operable with one or more processors. Networks 805-1 to805-N may be any wireless networks, including but not limited to widearea cellular networks, CSNs, PSNs, cellular packet data networks,wireless LANs, etc. that may employ known or hereto unknown radiotechnologies. Further, with respect to MCD 802, one or more networks maybe home networks or equivalent home networks, while one or more networksmay be visited or roaming networks, wherein each network's servinginfrastructure is illustrated as corresponding network nodes 804-1 to804-N. One or more network nodes may be provided with a power datahistory tracking logic and adjustment control module that may beimplemented in hardware, software, firmware or in any combination,operable with one or more processors, for tracking, monitoring andmaintaining the power data history relating to MCD 802. Referencenumerals 806-1 to 806-N refer to such structure and functionalityassociated with each network node. Depending on particularimplementation, a network node may be configured to provide appropriatetransmit power level and/or MCS adjustment control signals to MCD 802,whereby the uplink scheduling for the MCD can be performed optimally. Ina further variation, one or more network nodes may provide the powerdata history to another network node 810 at a different networkhierarchy (e.g., a service network 808) that includes centralizedadjustment control and/or power data history tracking logic 812. In astill further variation, MCD 802 may communicate with the servicenetwork node 810 and receive appropriate control signals therefrom.

Various processes, structures, components and functions set forth abovein detail, associated with one or more network nodes or a wireless UEdevice, may be embodied in software, firmware, hardware, or in anycombination thereof, and may accordingly comprise suitablecomputer-implemented methods or systems for purposes of the presentdisclosure. Where the processes are embodied in software, such softwaremay comprise program instructions that form a computer program product,instructions on a computer-accessible media, uploadable serviceapplication software, or software downloadable from a remote station,and the like. Further, where the processes, data structures, or both,are stored in computer accessible storage, such storage may includesemiconductor memory, internal and external computer storage media andencompasses, but is not limited to, nonvolatile media, volatile media,and transmission media. Nonvolatile media may include CD-ROMs, magnetictapes, PROMs, Flash memory, or optical media. Volatile media may includedynamic memory, caches, RAMs, etc. Transmission media may includecarrier waves or other signal-bearing media. As used herein, the phrase“computer-accessible medium” encompasses “computer-readable medium” aswell as “computer executable medium.”

It is believed that the operation and construction of the embodiments ofthe present patent application will be apparent from the DetailedDescription set forth above. While example embodiments have been shownand described, it should be readily understood that various changes andmodifications could be made therein without departing from the scope ofthe present disclosure as set forth in the following claims.

What is claimed is:
 1. A radiation power level control method for awireless user equipment (UE) device, said method comprising: determininga time-average transmission power level; comparing the time-averagetransmission power level with a first time-averaged transmission powerlimit threshold, the first time-averaged transmission power limitthreshold having a value that depends on a transmission power historyfor said UE device; and responsive to the time-average transmissionpower level meeting or exceeding the first time-averaged transmissionpower limit threshold, reducing a transmission power level of the UEdevice.
 2. The method of claim 1 wherein reducing a transmission powerlevel comprises reducing a number of transmission time slots used by theUE device.
 3. The method of claim 2 wherein reducing a transmissionpower level comprises retaining, within each of the reduced number oftransmission time slots, a time slot transmission power level that isconsistent with a time slot transmission power level used by the UEdevice prior to the reducing.
 4. The method of claim 1 wherein reducinga transmission power level comprises reducing a frame-averagetransmission power level, the frame-average transmission power levelbeing averaged over a single transmission frame comprising multiple timeslots, the time-average transmission power level being averaged overmultiple transmission frames.
 5. The method of claim 1 furthercomprising: in conjunction with reducing a transmission power level,retaining a first communication process and suspending a secondcommunication process.
 6. The method of claim 5 wherein the firstcommunication process comprises a voice call and the secondcommunication process comprises a data file transfer.
 7. The method ofclaim 5 further comprising: in conjunction with suspending the secondcommunication process, providing a notification to a user.
 8. The methodof claim 1 further comprising: in conjunction with reducing atransmission power level, changing a modulation and coding scheme (MCS)from a first MCS to a second MCS, the second MCS providing a lowerexpected bit-error-rate (BER) than a BER for the first MCS at thereduced transmission power level.
 9. The method of claim 1 furthercomprising: comparing the time-average transmission power level with asecond time-averaged transmission power limit threshold, the secondtime-averaged transmission power limit threshold having a lower valuethan the first time-averaged transmission power limit threshold; andresponsive to the time-average transmission power level meeting orfalling below the second time-averaged transmission power limitthreshold, increasing a transmission power level of the UE device. 10.The method of claim 9 wherein increasing a transmission power levelcomprises increasing a number of transmission time slots used by the UEdevice.
 11. The method of claim 9 further comprising: in conjunctionwith increasing a transmission power level, changing a modulation andcoding scheme (MCS) from a first MCS to a second MCS, the second MCSproviding a higher data rate than a data rate for the first MCS.
 12. Themethod of claim 1 further comprising: determining whether a currenttransmission event occurs within a predetermined duration window from aprior transmission event; responsive to determining that the currenttransmission event does occur within the predetermined duration window,including at least a portion of a transmission power level history ofthe prior transmission event in the determined average transmissionpower level; and responsive to determining that the current transmissionevent does not occur within the predetermined duration window, excludingthe transmission power level history of the prior transmission eventfrom the determined average transmission power level.
 13. The method ofclaim 1 further comprising: tracking at least one radiation historyparameter selected from the list consisting of: a time elapsed since aprior transmission event, a duration of the prior transmission event, afinal power level of the prior transmission event, a time-average powerlevel of the prior transmission event, and one or more antenna SpecificAbsorption Rate (SAR) values of the UE device.
 14. The method of claim 1further comprising: determining whether changing transmission from afirst antenna to a second antenna of the UE device will reduce aSpecific Absorption Rate (SAR) exposure of a user of the UE device; andresponsive to determining that changing transmission from the firstantenna to the second antenna will reduce a SAR exposure, ceasingtransmission from the first antenna and transmitting with the secondantenna.
 15. The method of claim 1 further comprising: determiningwhether the UE device is in use according to a private voice call mode;and responsive to determining that the UE device is not in use accordingto a private voice call mode, suspending comparison of the time-averagetransmission power level with a first time-averaged transmission powerlimit threshold.
 16. The method of claim 15 wherein determining whetherthe UE device is in use according to a private voice mode comprisesdetermining whether the UE device is holstered.
 17. The method of claim15 wherein determining whether the UE device is in use according to aprivate voice mode comprises determining whether the UE device is in useaccording to a speakerphone mode.
 18. The method of claim 17 whereindetermining whether the UE device is in use according to a speakerphonemode comprises determining at least one condition selected from the listconsisting of: the speakerphone speaker is activated; and anaccelerometer indicates a horizontal orientation of the UE device. 19.The method of claim 15 wherein determining whether the UE device is inuse according to a private voice mode comprises determining whether theUE device is in use according to a data entry mode.
 20. The method ofclaim 19 wherein determining whether the UE device is in use accordingto a data entry mode comprises determining at least one conditionselected from the list consisting of: a UE keyboard is registering keypresses at a rate that is consistent with typing by a user; and anaccelerometer indicates a data entry orientation of the UE device. 21.The method of claim 15 further comprising: responsive to determiningthat the UE device is not in use according to a private voice call mode,comparing the time-average transmission power level with an alternativepower limit threshold, different than the first time-averagedtransmission power limit threshold.
 22. The method of claim 1 furthercomprising: sending a message to a serving network node, said messagefor indicating a change in the transmission power level of the UEdevice.
 23. The method of claim 1 further comprising: sending a messageto a serving base station, said message for indicating a change in thetransmission power level of the UE device.
 24. The method of claim 1further comprising: reducing the first time-averaged transmission powerlimit threshold.
 25. A wireless user equipment (UE) device comprising: acomponent configured to determine a time-average transmission powerlevel of said wireless UE device; a component configured to compare thetime-average transmission power level with a first time-averagedtransmission power limit threshold, the first time-averaged transmissionpower limit threshold having a value that depends on a transmissionpower history for said UE device; and a component, operable responsiveto the average transmission power level meeting or exceeding the firsttime-averaged transmission power limit threshold, configured to reduce atransmission power level of the UE device.
 26. The wireless UE device ofclaim 25 wherein the component configured to reduce a transmission powerlevel comprises a component configured to reduce a number oftransmission time slots used by the UE device.
 27. The wireless UEdevice of claim 25 wherein reducing a transmission power level comprisesretaining, within each of the reduced number of transmission time slots,a time slot transmission power level that is consistent with a time slottransmission power level used by the UE device prior to the reducing.28. The wireless UE device of claim 25 wherein the component configuredto reduce a transmission power level comprises a component configured toreduce a frame-average transmission power level, the frame-averagetransmission power level being averaged over a single transmission framecomprising multiple time slots, the time-average transmission powerlevel being averaged over multiple transmission frames.
 29. The wirelessUE device of claim 25 further comprising: a component, operable inconjunction with reducing a transmission power level, configured toretain a first communication process and suspending a secondcommunication process.
 30. The wireless UE device of claim 29 whereinthe first communication process comprises a voice call and the secondcommunication process comprises a data file transfer.
 31. The wirelessUE device of claim 29 further comprising: a component, operable inconjunction with suspending the second communication process, configuredto provide a notification to a user.
 32. The wireless UE device of claim25 further comprising: a component, operable in conjunction withreducing a transmission power level, configured to change a modulationand coding scheme (MCS) from a first MCS to a second MCS, the second MCSproviding a lower expected bit-error-rate (BER) than a BER for the firstMCS at the reduced transmission power level.
 33. The wireless UE deviceof claim 25 further comprising: a component configured to compare thetime-average transmission power level with a second time-averagedtransmission power limit threshold, the second time-averagedtransmission power limit threshold having a lower value than the firsttime-averaged transmission power limit threshold; and a component,operable responsive to the time-average transmission power level meetingor falling below the second time-averaged transmission power limitthreshold, configured to increase a transmission power level of the UEdevice.
 34. The wireless UE device of claim 33 wherein increasing atransmission power level comprises increasing a number of transmissiontime slots used by the UE device.
 35. The wireless UE device of claim 33further comprising: a component, operable in conjunction with increasinga transmission power level, configured to change a modulation and codingscheme (MCS) from a first MCS to a second MCS, the second MCS providinga higher data rate than a data rate for the first MCS.
 36. The wirelessUE device of claim 25 further comprising: a component configured todetermine whether a current transmission event occurs within apredetermined duration window from a prior transmission event; acomponent, operable responsive to determining that the currenttransmission event does occur within the predetermined duration window,configured to include at least a portion of said transmission powerlevel history of the prior transmission event in the determined averagetransmission power level; and a component, operable responsive todetermining that the current transmission event does not occur withinthe predetermined duration window, configured to exclude thetransmission power level history of the prior transmission event fromthe determined average transmission power level.
 37. The wireless UEdevice of claim 25 further comprising: a component configured to trackat least one radiation history parameter selected from the listconsisting of: a time elapsed since a prior transmission event, aduration of the prior transmission event, a final power level of theprior transmission event, a time-average power level of the priortransmission event, and one or more antenna specific absorption rate(SAR) values of the UE device.
 38. The wireless UE device of claim 25further comprising: a component configured to determine whether changingtransmission from a first antenna to a second antenna will reduce aspecific absorption rate (SAR) exposure of a user of the UE device; anda component, operable responsive to determining that changingtransmission from the first antenna to the second antenna will reduce aSAR exposure, configured to cease transmission from the first antennaand transmitting with the second antenna.
 39. The wireless UE device ofclaim 25 further comprising: a component configured to determine whetherthe UE device is in use according to a private voice call mode; and acomponent, operable responsive to determining that the UE device is notin use according to a private voice call mode, configured to suspendcomparison of the time-average transmission power level with a firsttime-averaged transmission power limit threshold.
 40. The wireless UEdevice of claim 39 further comprising: a component, operable responsiveto determining that the UE device is not in use according to a privatevoice call mode, configured to compare the time-average transmissionpower level with an alternative power limit threshold, different thanthe first time-averaged transmission power limit threshold.
 41. Thewireless UE device of claim 25 further comprising: a componentconfigured to send a message to a serving network node said message forindicating a change in the transmission power level of the UE device.42. The wireless UE device of claim 25 further comprising: a componentconfigured to send a message to a serving base station, said message forindicating a change in the transmission power level of the UE device.43. The wireless UE device of claim 25 further comprising: a storageelement for storing a transmission power level history associated withsaid wireless UE device, said transmission power level historycomprising data tracked over a time window relative to one or morevariables.
 44. The wireless UE device of claim 25 further comprising: acomponent configured to reduce the first time-averaged transmissionpower limit threshold.